Efeito de microplásticos de poliestireno sobre a virulência de Candida albicans E Candida parapsilosis sensu stricto

Abstract

Environmental contamination by microplastics (MPs) and the high incidence of fungal infections caused by species of the genus Candida pose growing challenges to global health. The surfaces of these materials, by forming an ecological niche called the "plastisphere," can interact with pathogens in ways that are poorly understood. This study investigated the interference of polystyrene microplastics (100 nm) with the virulence factors of Candida albicans (ATCC 90028) and a clinical isolate of Candida parapsilosis sensu stricto (2-AGM). The objective was to evaluate the effects of microplastics on yeast virulence factors, with a focus on biofilm formation. The methodology consisted of in vitro assays to evaluate the effect of MPs on biofilm biomass, chitin and β-glucan composition of the extracellular matrix (ECM), susceptibility to the antifungal agents fluconazole, voriconazole, caspofungin, and amphotericin B, and hydrolytic enzyme activity. The results revealed that exposure to MPs promoted a significant increase in biofilm biomass in both species, indicating that the particles play a role in the maturation of the three dimensional structure. The Minimum Inhibitory Concentration (MIC) of caspofungin and fluconazole increased for C. parapsilosis. A metabolic redirection was observed in the ECM, with a decrease in chitin levels and significant accumulation of β-glucan. This structural alteration of the matrix promoted a significant increase in biofilm resistance to all antifungal agents tested. Enzymatic activity varied between groups, with a notable increase in proteinase and hemolysin production in C. parapsilosis. It is concluded that microplastics can act as modulators of the virulence of Candida species, enhancing the formation of robust and multidrug-resistant biofilms through remodeling of the extracellular matrix. This work establishes a relationship between plastic pollution and fungal virulence, highlighting an emerging risk factor for human health.